Why would be air flow control buttons stop working? My fan speed, AC and heater controls all work fine, but I can’t change vents?
Depending upon the model year of this mystery vintage Outback, it is very likely that the servo motors that change the direction of the “doors” in the HVAC system are activated by vacuum from the engine.
Translation: One of more vacuum hoses are disconnected or cracked.
However, vacuum controls later gave way to electrically-activated doors in the HVAC system, so depending upon the actual model year of this car, it is also possible that an electrical servo motor has failed.
Thank you! And I’m sorry for leaving out its a 1999 Subaru Legacy Outback